Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Many thanks to Fred Seidel <seidel@metabox.de>, the |
| 3 | * designer of the RDS decoder hardware. With his help |
| 4 | * I was able to code this driver. |
| 5 | * Thanks also to Norberto Pellicci, Dominic Mounteney |
| 6 | * <DMounteney@pinnaclesys.com> and www.teleauskunft.de |
| 7 | * for good hints on finding Fred. It was somewhat hard |
| 8 | * to locate him here in Germany... [: |
| 9 | * |
| 10 | * Revision history: |
| 11 | * |
| 12 | * 2000-08-09 Robert Siemer <Robert.Siemer@gmx.de> |
| 13 | * RDS support for MiroSound PCM20 radio |
| 14 | */ |
| 15 | |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/errno.h> |
| 18 | #include <linux/string.h> |
| 19 | #include <linux/init.h> |
| 20 | #include <linux/slab.h> |
Ingo Molnar | 3593cab | 2006-02-07 06:49:14 -0200 | [diff] [blame] | 21 | #include <linux/mutex.h> |
| 22 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <asm/io.h> |
| 24 | #include "../../../sound/oss/aci.h" |
| 25 | #include "miropcm20-rds-core.h" |
| 26 | |
| 27 | #define DEBUG 0 |
| 28 | |
Ingo Molnar | 3593cab | 2006-02-07 06:49:14 -0200 | [diff] [blame] | 29 | static struct mutex aci_rds_mutex; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
| 31 | #define RDS_DATASHIFT 2 /* Bit 2 */ |
| 32 | #define RDS_DATAMASK (1 << RDS_DATASHIFT) |
| 33 | #define RDS_BUSYMASK 0x10 /* Bit 4 */ |
| 34 | #define RDS_CLOCKMASK 0x08 /* Bit 3 */ |
| 35 | |
| 36 | #define RDS_DATA(x) (((x) >> RDS_DATASHIFT) & 1) |
| 37 | |
| 38 | |
| 39 | #if DEBUG |
| 40 | static void print_matrix(char array[], unsigned int length) |
| 41 | { |
| 42 | int i, j; |
| 43 | |
| 44 | for (i=0; i<length; i++) { |
| 45 | printk(KERN_DEBUG "aci-rds: "); |
| 46 | for (j=7; j>=0; j--) { |
| 47 | printk("%d", (array[i] >> j) & 0x1); |
| 48 | } |
| 49 | if (i%8 == 0) |
| 50 | printk(" byte-border\n"); |
| 51 | else |
| 52 | printk("\n"); |
| 53 | } |
| 54 | } |
| 55 | #endif /* DEBUG */ |
| 56 | |
| 57 | static int byte2trans(unsigned char byte, unsigned char sendbuffer[], int size) |
| 58 | { |
| 59 | int i; |
| 60 | |
| 61 | if (size != 8) |
| 62 | return -1; |
| 63 | for (i = 7; i >= 0; i--) |
| 64 | sendbuffer[7-i] = (byte & (1 << i)) ? RDS_DATAMASK : 0; |
| 65 | sendbuffer[0] |= RDS_CLOCKMASK; |
| 66 | |
| 67 | return 0; |
| 68 | } |
| 69 | |
| 70 | static int rds_waitread(void) |
| 71 | { |
| 72 | unsigned char byte; |
| 73 | int i=2000; |
| 74 | |
| 75 | do { |
| 76 | byte=inb(RDS_REGISTER); |
| 77 | i--; |
| 78 | } |
| 79 | while ((byte & RDS_BUSYMASK) && i); |
| 80 | |
| 81 | if (i) { |
| 82 | #if DEBUG |
| 83 | printk(KERN_DEBUG "rds_waitread()"); |
| 84 | print_matrix(&byte, 1); |
| 85 | #endif |
| 86 | return (byte); |
| 87 | } else { |
| 88 | printk(KERN_WARNING "aci-rds: rds_waitread() timeout...\n"); |
| 89 | return -1; |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | /* don't use any ..._nowait() function if you are not sure what you do... */ |
| 94 | |
| 95 | static inline void rds_rawwrite_nowait(unsigned char byte) |
| 96 | { |
| 97 | #if DEBUG |
| 98 | printk(KERN_DEBUG "rds_rawwrite()"); |
| 99 | print_matrix(&byte, 1); |
| 100 | #endif |
| 101 | outb(byte, RDS_REGISTER); |
| 102 | } |
| 103 | |
| 104 | static int rds_rawwrite(unsigned char byte) |
| 105 | { |
| 106 | if (rds_waitread() >= 0) { |
| 107 | rds_rawwrite_nowait(byte); |
| 108 | return 0; |
| 109 | } else |
| 110 | return -1; |
| 111 | } |
| 112 | |
| 113 | static int rds_write(unsigned char cmd) |
| 114 | { |
| 115 | unsigned char sendbuffer[8]; |
| 116 | int i; |
| 117 | |
| 118 | if (byte2trans(cmd, sendbuffer, 8) != 0){ |
| 119 | return -1; |
| 120 | } else { |
| 121 | for (i=0; i<8; i++) { |
| 122 | rds_rawwrite(sendbuffer[i]); |
| 123 | } |
| 124 | } |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | static int rds_readcycle_nowait(void) |
| 129 | { |
| 130 | rds_rawwrite_nowait(0); |
| 131 | return rds_waitread(); |
| 132 | } |
| 133 | |
| 134 | static int rds_readcycle(void) |
| 135 | { |
| 136 | if (rds_rawwrite(0) < 0) |
| 137 | return -1; |
| 138 | return rds_waitread(); |
| 139 | } |
| 140 | |
| 141 | static int rds_read(unsigned char databuffer[], int datasize) |
| 142 | { |
| 143 | #define READSIZE (8*datasize) |
| 144 | |
| 145 | int i,j; |
| 146 | |
| 147 | if (datasize < 1) /* nothing to read */ |
| 148 | return 0; |
| 149 | |
| 150 | /* to be able to use rds_readcycle_nowait() |
| 151 | I have to waitread() here */ |
| 152 | if (rds_waitread() < 0) |
| 153 | return -1; |
| 154 | |
| 155 | memset(databuffer, 0, datasize); |
| 156 | |
| 157 | for (i=0; i< READSIZE; i++) |
| 158 | if((j=rds_readcycle_nowait()) < 0) { |
| 159 | return -1; |
| 160 | } else { |
| 161 | databuffer[i/8]|=(RDS_DATA(j) << (7-(i%8))); |
| 162 | } |
| 163 | |
| 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | static int rds_ack(void) |
| 168 | { |
| 169 | int i=rds_readcycle(); |
| 170 | |
| 171 | if (i < 0) |
| 172 | return -1; |
| 173 | if (i & RDS_DATAMASK) { |
| 174 | return 0; /* ACK */ |
| 175 | } else { |
| 176 | printk(KERN_DEBUG "aci-rds: NACK\n"); |
| 177 | return 1; /* NACK */ |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | int aci_rds_cmd(unsigned char cmd, unsigned char databuffer[], int datasize) |
| 182 | { |
| 183 | int ret; |
| 184 | |
Ingo Molnar | 3593cab | 2006-02-07 06:49:14 -0200 | [diff] [blame] | 185 | if (mutex_lock_interruptible(&aci_rds_mutex)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | return -EINTR; |
| 187 | |
| 188 | rds_write(cmd); |
| 189 | |
| 190 | /* RDS_RESET doesn't need further processing */ |
| 191 | if (cmd!=RDS_RESET && (rds_ack() || rds_read(databuffer, datasize))) |
| 192 | ret = -1; |
| 193 | else |
| 194 | ret = 0; |
| 195 | |
Ingo Molnar | 3593cab | 2006-02-07 06:49:14 -0200 | [diff] [blame] | 196 | mutex_unlock(&aci_rds_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | |
| 198 | return ret; |
| 199 | } |
| 200 | EXPORT_SYMBOL(aci_rds_cmd); |
| 201 | |
| 202 | int __init attach_aci_rds(void) |
| 203 | { |
Ingo Molnar | 3593cab | 2006-02-07 06:49:14 -0200 | [diff] [blame] | 204 | mutex_init(&aci_rds_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | return 0; |
| 206 | } |
| 207 | |
| 208 | void __exit unload_aci_rds(void) |
| 209 | { |
| 210 | } |
| 211 | MODULE_LICENSE("GPL"); |